Terminal and contact construction for electric switches



Aug? 5, i1952 E. N. JACOBI 2,606,264

TERMINAL AND CONTACT CONSTRUCTION FOR ELECTRIC SWITCHES Filed Nov. 10,1949 l 7 II! I MGM Patented Aug. 5, 1952 TERMINAL AND CONTACTCONSTRUCTION FOR ELECTRIC SWITCHES Edward N. Jacobi, Milwaukee, Wis.,assignor to Briggs & Stratton Corporation, Milwaukee, Wis., acorporation of Delaware Application November 10, 1949, Serial No.126,468

This invention relates to electric switches and refers more particularlyto a terminal and contact construction for switches of the type formingthe subject matter of the copending application of .Edward N. Jacobi,Serial No. 123,709, filed October 26, 1949.

One of the objects of this invention is to provide a simple, inexpensivecontact and terminal construction for such switches by which a conductorcan be directlyconnected to the terminal portion in a mannerfacilitating the use of armored protection for the conductors Anotherobject of this invention'is to provide an improved contact and terminalmember wherein the terminal portion has a part arranged to be clampedand clinched to the bared end portion of a conductor and another partsimilarly engageable with the insulated portion of the conductor tofirmly anchor and electrically connect the contact and terminal memberto the conductor in a manner which permits the entire connection to bereceivedin a hole or pocket in the terminal head leaving the back of theterminal head free for theattachment of an armor sheath for theconductor.

Still another object of this invention is to provide a contact andterminal member of the character described which is so designed thatupon its assembly with the terminal head it retains its positionfrictionally and thus facilitates assembly of the parts.

With the above and other objects in view, which willappear as thedescription proceeds, this invention resides in the novel construction,combination and arrangement of parts substantially as hereinafterdescribed and more particularly defined by the appended claims, it beingunderstood that such changes in the precise embodiment of thehereindisclosed invention may be made as come within the scope of theclaims.

The accompanying drawing illustrates one complete example of thephysical embodiment of the invention constructed according to the bestmode so far devised for the practical application of the principlesthereof, and in which:

Figure 1 is a side elevational view of a portion of a switch of the typeto which this invention pertains having a part thereof broken away toillustrate the details of the combined contact and terminal member perse;

Figure 2 is a fragmentary cross sectional view through Figure l on theplane of the line 2-2 which is directly ahead of the disc in which thestationary contacts of the switch are mounted, part of said disc beingbroken away;

5 Claims. (01. 200-166) Figure 3 is a detail sectional view takenthrough Figure 1 on the plane of the line 33; and

Figure 4 is a perspective view of the combined contact and terminalmember per se.

Referring now particularly to the accompanying drawing the numeral 4designates the case or housing of the switch which, as more fullydescribed in the aforesaid copending application, houses a rotarycontactor 5, part of which is shown in Figure 1, a lock (not shown) anda coupling (also not shown)v through which rotation of the lock cylinderis transmitted to the rotary contactor 5.

The contactor 5 has a plurality of contacts arranged to slide across thestationary contact face provided by a fiat disc 5 of insulating materialwhich overlies the fiat front face of a terminal head i. The terminalhead 1 is molded from suitable insulating material while the disc 6 isstamped from sheet stock having better wearing qualities than the moldedterminal head.

In the assembled condition of the switch shown in Figure 1 the disc 6 isclamped between the fiat front face of the terminal head and a shoulder8 formed in the case or housing 4, the termi nal head being held inplace by clinching over the marginal edge of the case or housing.

Though the terminal head mounts a number of stationary contacts thepresent invention concerns only one of these, and when the switch isused as an ignition switch for automobiles this contact is the ignitioncontact and is connected with the ignition coil through an armoredconductor 9. The armored conductor, of course, includes a conductor wireIn covered with insulation H and a metal sheath l2.

It is, of course, important that the overall size of the switch be heldto a minimum and that the connection between the conductor 9 and itscontact be protected as well as the conductor. The present inventionachieves this objective in a simple and expeditious manner and to thisend provides a combined contact and terminal member I3 stamped andformed from suitable sheet metal and designed to be mounted entirelywithin the terminal head. To accommodate the combined contact andterminal member the terminal head has a cavity l4 opening to its flatfront face and a hole l5 leading from the bottom of the cavity andextending through the terminal head to the back thereof; and the disc 6has a hole [6 in line with but smaller than the mouth of the cavity.Portions of the cavity are thus covered by the disc.

The contact portion I! of the member I3 is flat and fits within the hole16 in the disc. At one side edge thereof the contact portion [1 has twolocating lugs or ears l8 projecting therefrom. These lugs are offsetrearwardly an amount such that their flat front faces are spaced fromthe plane of the outer front face of the contact portion [Ta distanceequal to the thickness of the disc 6.

The opposite side edge of the contact portion H has an offset part 19extended therefrom, the extent of its offset, however, being less thanthat of the lugs l8 so that the part [9 lies between the faces of thedisc =6 in a bay 2G in one side of the hole [6. The part i9 is bentperpendicularly as at 2| and then again at right angles to'form aportion 22 parallel to and overlying the part l9 7 and the contactportion H. The portions 19, 2 iand 22 thus together define substantiallya U- shaped or channel-like structure with theportion 2 I serving as theweb thereof.

The opposite ends of this web portion 2| are extended to providelocating lugs 23 which are bent inwardly, as best shown in Figure 2, tolie in planes defining an obtuse angle between them. The purpose of thisangular disposition of the lugs 23 will be brought out hereinafter. Atthis point it is desired to direct attention to the fact that the frontedges 24 of the lugs 23 are parallel to and spaced from the front faceof the contact portion ll the same distance as are the outer faces ofthe lugs 18. Hence, when these edges 24 and the front faces of the lugsl8 lie flat against the underside or rear face of the disc 5, the frontface of the contact portion l? is flush with the front face of the disc.

The cavity l4 and hole i5 in the terminal head accommodate the portionsof the combined contact and terminal member 53 lying beneath orrearwardly of the disc 8. One side portion of the cavity receives thelugs l8. The opposite side portion of the cavity, which is deeper,receives the channel-shaped part of the member l3, and the angularlybent lugs or ears 23 are received in pockets or lateral extensions 25 atthis side of the cavity.

The pockets 25, of course, open to the fiat front face of the terminalhead and have opposite parallel side walls 26 perpendicular to the frontface of the terminal head. The space between these side walls 26 isslightly less than the distance between the plane of the outer face ofthe web portion 2! and the edges of the lugs farthest removed from saidplane. Hence, it will be readily apparent that with the combined contactand terminal member in place the outer face of the web portion 2! liesflat against the adjacent side of the cavity and the lugs 23 areconfined between the walls 25 of the pockets 25. This necessitatesslight flexing of the lugs 23 and this slight flexing or tension.frictionally holds the combined contact and terminal member assembledwith the terminal head during assembly of the parts.

It is to be understood that the relative sizes of the mouth of thecavity M including its lateral extensions or pockets 25 and the hole [6with its bay 2B are such that the pockets 25 and those portions of thecavity in which the lugs I8 are disposed are covered by the disc,thereby enabling the lugs l8 and 23 to engage the underside of the discand hold its contact portion l'l against outward displacement beyond aposition at which its front face is flush with the front face of thedisc.

Two bosses or pads 2'? formed integrally with the terminal head andrising from its flat front face engage the back or underside of thecontact portion l1 near its opposite ends to coact with the lugs I8 and23 in holding the contact portion l1 firmly in proper position.

The terminal portion 28 of the member 13 extends perpendicularly fromits part 22 and is substantially channel-shaped in cross section withthe sidesof the channelshaped to provide two sets of clinching arms 29and 30, the latter being shortest and nearest to the terminal portionI1. These clinching arms 29 and 30 are adapted to be folded over theinsulation and bared end portion of the conductor to thus firmly anchorthe member [3 to .the conductor and establish a good electricalconnection between it and the contact member.

With thearms 29 and 30 folded and clinched over the conductor asdescribed, the actual connection between the terminal and the conductoris hardly larger in diameter than the conductor itself. Hence, it maybeconveniently received within the hole l5 in the'terminal head leavingthe back of the terminal head unobstructed for anchorage of the armoredsheath l2, and while the specific manner'in which the sheath is anchoredforms no part of this invention it is to be noted that its reception ina ferrule 3| which in turn is securedto a stamped cap 32 allows thesheath to be secured to the back of the terminal head in a way whichaffords complete protection for the conductor'and its connection to thecontact and terminal member I3.

From the foregoing description taken with the accompanyin drawing itwill be readily apparent to those skilled in this art that the novelcombined contact and terminal memberof this invention, and the manner inwhich it is mounted on the terminal head and connected to its wire leadachieves remarkable simplicity and compactness in addition to many otheradvantages including low cost.

What I claim as my invention is:

1. In an electric switch: a terminal head having a flat front face and.a cavity opening to said flat front face, said cavity having opposedpockets opening to the front face of the terminal head and each havingside walls substantially perpendicular to said front face, said terminalhead also having a hole therethrough leading from the bottom of thecavity; a disc of insulating material overlying the flat front face ofthe terminal head, said disc having a hole therethrough substantially inline with the cavity but smaller than the mouth of the. cavity so thatportions of the cavity including said opposed pockets are covered by thedisc; a combination contact and terminal memberhaving a fiat contactportion received in the hole in the disc; lugs extended from one sideedge of the contact portion and engaging the underside of the disc, saidlugs being received in that portion of the cavity covered by the portionof the disc which the lugs underlie; other lugs extended from a partconnected to the contact portion, said other lugs lying in planesperpendicular to the fiat contact portion and being bent to define anobtuse angle therebetween, said other lugs being received in the pocketsof the cavity and frictionally engaging the opposite side walls thereof;and a terminal portion extending from said part from which said otherlugs project, received in the hole in the terminal head and to which aconductor may be connected.

2. The structure set forth in claim 1 further characterized by the factthat said other lugs engage the underside of the disc portions coveringthe pockets in which they are disposed, and by the fact that all of saidlugs have their portions which engage the underside of the disc spacedfrom the plane of the flat front face of the contact portion a distanceequal to the thickness of the disc; and a boss on the terminal headengaging the underside of the contact portion and of a height to holdthe lugs snugly against the underside of the disc when said disc liesflat against the front face of the terminal head.

3. As an article of manufacture, a combined contact and terminal memberfor electric switches, comprising: a sheet metal stamping having a flatcontact portion; spaced locating lugs extending from one side edge ofthe contact portion and having flat surfaces offset rearwardly from andlying in a plane parallel to the front face of the contact portion; alateral projection extending from the other side edge of the contactportion also oifset rearwardly from the contact portion, said projectionbeing shaped to have a rearwardly directed portion substantiallyperpendicular to the plane of the contact portion, and a part extendingfrom the rear edge of the rearwardly directed portion and overlying butspaced from the contact portion so that said projection is substantiallychannel-shaped, and said part, which provides the rear flange of thechannel, having a terminal portion extending rearwardly therefrom; theopposite ends of the web or bottom of the channel being extended andbent inwardly at an obtuse angle to the web or bottom of the channel toprovide another set of locating lugs, lying in planes perpendicular tothat of the contact portion and the front edges of which lie in the sameplane occupied by the fiat surfaces of the first-mentioned locatinglugs; and means on the terminal portion for securing a conductor theretoin good electrical contact therewith.

4. As an article of manufacture, a combined contact and terminal memberfor electric switches, comprising: a sheet metal stamping having a, flatcontact portion; a fiat mounting portion extending rearwardly from oneside edge of the contact portion, substantially perpendicular to theplane of the contact portion; lugs extending from said mounting portion,bent out of the plane thereof, at an obtuse angle thereto, and lying inplanes perpendicular to the plane of the contact portion, said lugshaving their front edges disposed'in a common plane parallel to that ofthe contact portion and spaced rearwardly thereof; a terminal portionextending rearwardly from said mounting portion; and means on saidterminal portion for securing a conductor thereto in good electricalcontact therewith.

5. In an electric switch: a terminal head having a, fiat front surfaceand having a cavity opening to said fiat surface, said cavity includingan elongated pocket opening to the front surface of the terminal head,which pocket has opposed side walls perpendicular to said front surface,said terminal head also having a hole leading from the bottom of thecavity and extending through the terminal head; a disc of insulatingmaterial overlying and in flat surface-to-surface engagement with thefront surface of the terminal head, said disc having a hole therethroughsmaller than the mouth of the cavity and in line with the cavity so thatportions of the mouth of the cavity are covered by the disc; a stampedand formed sheet metal contact and terminal member having a flat contactportion received in the hole in the disc; a mounting member extendingfrom one side edge of the contact portion and having a fiat portionperpendicular to the contact portion overlying one side Wall of saidpocket in the terminal head; lugs extending from said flat portion ofthe mounting member at obtuse angles thereto and lying in planesperpendicular to the contact portion, with a free edge of each lugfrictionally engaging a side wall of said pocket opposite to thatengaged by said flat portion of the mounting member to thereby hold thecontact and terminal member assembled with the terminal head; and aterminal portion received in said hole through the terminal head and towhich a conductor may be secured.

EDWARD N. J ACOBI.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 7 2,142,818 Jacobson Jan. 3, 19392,186,638 Hall Jan. 9, 1940 2,427,277 flasselbaum net-P Sept. 9, 1947

